1. Field of the Invention
The present invention relates to polypeptides having glucoamylase activity, catalytic domains, and carbohydrate binding domains, and polynucleotides encoding the polypeptides, catalytic domains, and carbohydrate binding domains. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides, catalytic domains, and carbohydrate binding domains.
2. Description of the Related Art
Glucoamylase (1,4-alpha-D-glucan glucohydrolase, EC 3.2.1.3) is an enzyme, which catalyzes the release of D-glucose from the non-reducing ends of starch or related oligo- and polysaccharide molecules. Glucoamylases are produced by several filamentous fungi and yeast, with those from Aspergillus being commercially most important.
Commercially, glucoamylases are used to convert starchy material, which is already partially hydrolyzed by an alpha-amylase, to glucose. The glucose may then be converted directly or indirectly into a fermentation product using a fermenting organism. Examples of commercial fermentation products include alcohols (e.g., ethanol, methanol, butanol, 1,3-propanediol); organic acids (e.g., citric acid, acetic acid, itaconic acid, lactic acid, gluconic acid, gluconate, lactic acid, succinic acid, 2,5-diketo-D-gluconic acid); ketones (e.g., acetone); amino acids (e.g., glutamic acid); gases (e.g., H2 and CO2), and more complex compounds, including, for example, antibiotics (e.g., penicillin and tetracycline); enzymes; vitamins (e.g., riboflavin, B12, beta-carotene); hormones, and other compounds which are difficult to produce synthetically. Fermentation processes are also commonly used in the consumable alcohol (e.g., beer and wine), dairy (e.g., in the production of yogurt and cheese) industries.
The end product may also be a syrup. For instance, the end product may be glucose, but may also be converted, e.g., by a glucose isomerase to fructose or a mixture composed almost equally of glucose and fructose. This mixture, or a mixture further enriched with fructose, is the most commonly used high fructose corn syrup (HFCS) commercialized throughout the world.
It is an object of the present invention to provide further polypeptides having glucoamylase activity and polynucleotides encoding the polypeptides. The present invention provides polypeptides having glucoamylase activity and polynucleotides encoding the polypeptides.
WO 2006/069289 discloses a glucoamylase from Trametes cingulata having 75.32% identity to the mature polypeptide according to the invention.
WO 2011/068803 discloses a glucoamylase from Gloeophillum sepiarium having 75.86% identity to the mature polypeptide according to the invention.